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    Length: 4633 (0x1219)
    Types: TextFile
    Notes: R1k Text-file segment

└─⟦8527c1e9b⟧ Bits:30000544 8mm tape, Rational 1000, Arrival backup of disks in PAM's R1000
    └─ ⟦cfc2e13cd⟧ »Space Info Vol 2« 
        └─⟦595c80207⟧ 
            └─⟦this⟧ 

TextFile

with a_strings;
with os_files;    use os_files;
with system;
with v_i_mutex;

package file_support is

	stdin_fd: file_descriptor renames os_files.stdin_fd;
	stdout_fd: file_descriptor renames os_files.stdout_fd;
	stderr_fd: file_descriptor renames os_files.stderr_fd;
	function sequential return os_files.file_styles renames os_files.sequential;
	function direct return os_files.file_styles renames os_files.direct;
	function text return os_files.file_styles renames os_files.text;
	function "="(a, b: file_id_ptr) return boolean
		renames os_files."=";
	function same_id(a, b: file_id_ptr) return boolean
		renames os_files.same_id;
	function file_size(fd: file_descriptor; elem_size: integer) return integer
		renames os_files.file_size;
	function is_interactive(fd: file_descriptor) return boolean
		renames os_files.is_interactive;
	procedure position_file(fd: file_descriptor; to, size: integer)
		renames os_files.position_file;
	procedure skip_in_file(fd: file_descriptor; to: integer)
		renames os_files.skip_in_file;
	function read(fd: file_descriptor; addr: system.address; cnt: integer)
		return integer renames os_files.read;
	procedure write(fd: file_descriptor; addr: system.address; cnt:integer)
		renames os_files.write;
	function get_file_id(fd: file_descriptor) return os_files.file_id_ptr
		renames os_files.get_file_id;

	type byte_array is array(natural range <>) of character;
	type buffer_rec(size : natural) is 
		record
			 -- elem(0) is used for pushing in ascii.lf
			 -- after read-ahead.  buffer really starts at elem(1).
			 elem	: byte_array(0..size);
		end record;
	type access_bytes is access buffer_rec;

	type access_char is access character;

	type file_mode is (input, output, in_out);

	type file_pos is (unknown, at_char, at_eol, at_delayed_eol, at_eop, at_eof);
	
	type file_record;
	
	type file_ptr is access file_record;

	type file_record is
		record
			fd			: file_descriptor;
			name		: a_strings.a_string;
			mode		: file_mode;
			form		: a_strings.a_string;
			style		: file_styles;
			resetable	: boolean;
			index		: natural;
			linelength	: natural;
			pagelength	: natural;
			line		: natural;
			page		: natural;
			pos			: file_pos;
			delete		: boolean;
			file_id		: file_id_ptr;
			eof_char	: character;
			test_eof	: boolean := false;

			-- for buffering in the file.
			buffer		: access_bytes;
			last		: integer := -1;
			last_lf		: integer := -1;
			in_ptr		: integer := -1;
			out_ptr		: integer := -1;
			always_flush: boolean;

            -- for get_line returning form feeds in the returned string
            want_ff     : boolean := false;

			-- for linked list of file descriptors: all open files
			next		: file_ptr;

			-- for task and abort safe file I/O
			mutex		: v_i_mutex.safe_mutex_t;

		end record;

	-- Access to file_list must be protected via
	-- safe_support.file_support_lock().
	file_list: file_ptr := null;

	-- The following are updated in text_io
	cur_input_id	: file_id_ptr;
	cur_output_id	: file_id_ptr;

	-- The file routines need to be safe_support.file_lock()'ed as follows:
	--  file_open(), setup_buffer()		=>
	--  	upon entry/exit: unlocked
	--  file_close_upon_exit()			=>
	--  	upon entry/exit: unlocked
	--  file_close(), file_delete()		=>
	--  	upon entry: locked, upon exit unlocked
	--  all other file routines			=>
	--  	upon entry/exit: locked

    procedure file_open(name : string := "";
						file : in out file_ptr;
						mode : file_mode := in_out;
						create : boolean := false;
						form : string := "";
						style : file_styles := text;
						record_size: integer := 0);

    procedure file_close(file : in out file_ptr);
    procedure file_delete(file : in out file_ptr);
    procedure file_reset(file : in out file_ptr; mode : file_mode);

	-- Called at program exit from close_all(). Doesn't do any
	-- locks/unlocks or frees
    procedure file_close_upon_exit(file : file_ptr);

    function file_eof(file : in file_ptr) return boolean;

	procedure putchar(file : file_ptr; char : character);
	function getchar(file : file_ptr) return character;
	procedure skip_past_eol(file: file_ptr);
	function tstfile(file : file_ptr) return file_pos;
	function tstfile_beyond_eol(file : file_ptr) return file_pos;
	procedure setup_buffer(file : file_ptr; size: natural);
	procedure refill_buffer(file : file_ptr);

	procedure always_flush(file: file_ptr);
	procedure want_ff(file: file_ptr);
	procedure flush(file: file_ptr);
	procedure set_buffer_size(file: file_ptr; size: natural);
	procedure set_eof_char(file:file_ptr; eof_char: character := ascii.eot);

	procedure write_to_stderr(message: string);

end file_support